<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="generator" content="Docutils 0.8.1: http://docutils.sourceforge.net/" />
<title>Graphic User Interface FAQ</title>
<meta name="date" content="2003-09-04" />
<style type="text/css">

/*
:Author: David Goodger (goodger@python.org)
:Id: $Id: html4css1.css 7056 2011-06-17 10:50:48Z milde $
:Copyright: This stylesheet has been placed in the public domain.

Default cascading style sheet for the HTML output of Docutils.

See http://docutils.sf.net/docs/howto/html-stylesheets.html for how to
customize this style sheet.
*/

/* used to remove borders from tables and images */
.borderless, table.borderless td, table.borderless th {
  border: 0 }

table.borderless td, table.borderless th {
  /* Override padding for "table.docutils td" with "! important".
     The right padding separates the table cells. */
  padding: 0 0.5em 0 0 ! important }

.first {
  /* Override more specific margin styles with "! important". */
  margin-top: 0 ! important }

.last, .with-subtitle {
  margin-bottom: 0 ! important }

.hidden {
  display: none }

a.toc-backref {
  text-decoration: none ;
  color: black }

blockquote.epigraph {
  margin: 2em 5em ; }

dl.docutils dd {
  margin-bottom: 0.5em }

object[type="image/svg+xml"], object[type="application/x-shockwave-flash"] {
  overflow: hidden;
}

/* Uncomment (and remove this text!) to get bold-faced definition list terms
dl.docutils dt {
  font-weight: bold }
*/

div.abstract {
  margin: 2em 5em }

div.abstract p.topic-title {
  font-weight: bold ;
  text-align: center }

div.admonition, div.attention, div.caution, div.danger, div.error,
div.hint, div.important, div.note, div.tip, div.warning {
  margin: 2em ;
  border: medium outset ;
  padding: 1em }

div.admonition p.admonition-title, div.hint p.admonition-title,
div.important p.admonition-title, div.note p.admonition-title,
div.tip p.admonition-title {
  font-weight: bold ;
  font-family: sans-serif }

div.attention p.admonition-title, div.caution p.admonition-title,
div.danger p.admonition-title, div.error p.admonition-title,
div.warning p.admonition-title {
  color: red ;
  font-weight: bold ;
  font-family: sans-serif }

/* Uncomment (and remove this text!) to get reduced vertical space in
   compound paragraphs.
div.compound .compound-first, div.compound .compound-middle {
  margin-bottom: 0.5em }

div.compound .compound-last, div.compound .compound-middle {
  margin-top: 0.5em }
*/

div.dedication {
  margin: 2em 5em ;
  text-align: center ;
  font-style: italic }

div.dedication p.topic-title {
  font-weight: bold ;
  font-style: normal }

div.figure {
  margin-left: 2em ;
  margin-right: 2em }

div.footer, div.header {
  clear: both;
  font-size: smaller }

div.line-block {
  display: block ;
  margin-top: 1em ;
  margin-bottom: 1em }

div.line-block div.line-block {
  margin-top: 0 ;
  margin-bottom: 0 ;
  margin-left: 1.5em }

div.sidebar {
  margin: 0 0 0.5em 1em ;
  border: medium outset ;
  padding: 1em ;
  background-color: #ffffee ;
  width: 40% ;
  float: right ;
  clear: right }

div.sidebar p.rubric {
  font-family: sans-serif ;
  font-size: medium }

div.system-messages {
  margin: 5em }

div.system-messages h1 {
  color: red }

div.system-message {
  border: medium outset ;
  padding: 1em }

div.system-message p.system-message-title {
  color: red ;
  font-weight: bold }

div.topic {
  margin: 2em }

h1.section-subtitle, h2.section-subtitle, h3.section-subtitle,
h4.section-subtitle, h5.section-subtitle, h6.section-subtitle {
  margin-top: 0.4em }

h1.title {
  text-align: center }

h2.subtitle {
  text-align: center }

hr.docutils {
  width: 75% }

img.align-left, .figure.align-left, object.align-left {
  clear: left ;
  float: left ;
  margin-right: 1em }

img.align-right, .figure.align-right, object.align-right {
  clear: right ;
  float: right ;
  margin-left: 1em }

img.align-center, .figure.align-center, object.align-center {
  display: block;
  margin-left: auto;
  margin-right: auto;
}

.align-left {
  text-align: left }

.align-center {
  clear: both ;
  text-align: center }

.align-right {
  text-align: right }

/* reset inner alignment in figures */
div.align-right {
  text-align: inherit }

/* div.align-center * { */
/*   text-align: left } */

ol.simple, ul.simple {
  margin-bottom: 1em }

ol.arabic {
  list-style: decimal }

ol.loweralpha {
  list-style: lower-alpha }

ol.upperalpha {
  list-style: upper-alpha }

ol.lowerroman {
  list-style: lower-roman }

ol.upperroman {
  list-style: upper-roman }

p.attribution {
  text-align: right ;
  margin-left: 50% }

p.caption {
  font-style: italic }

p.credits {
  font-style: italic ;
  font-size: smaller }

p.label {
  white-space: nowrap }

p.rubric {
  font-weight: bold ;
  font-size: larger ;
  color: maroon ;
  text-align: center }

p.sidebar-title {
  font-family: sans-serif ;
  font-weight: bold ;
  font-size: larger }

p.sidebar-subtitle {
  font-family: sans-serif ;
  font-weight: bold }

p.topic-title {
  font-weight: bold }

pre.address {
  margin-bottom: 0 ;
  margin-top: 0 ;
  font: inherit }

pre.literal-block, pre.doctest-block, pre.math {
  margin-left: 2em ;
  margin-right: 2em }

span.classifier {
  font-family: sans-serif ;
  font-style: oblique }

span.classifier-delimiter {
  font-family: sans-serif ;
  font-weight: bold }

span.interpreted {
  font-family: sans-serif }

span.option {
  white-space: nowrap }

span.pre {
  white-space: pre }

span.problematic {
  color: red }

span.section-subtitle {
  /* font-size relative to parent (h1..h6 element) */
  font-size: 80% }

table.citation {
  border-left: solid 1px gray;
  margin-left: 1px }

table.docinfo {
  margin: 2em 4em }

table.docutils {
  margin-top: 0.5em ;
  margin-bottom: 0.5em }

table.footnote {
  border-left: solid 1px black;
  margin-left: 1px }

table.docutils td, table.docutils th,
table.docinfo td, table.docinfo th {
  padding-left: 0.5em ;
  padding-right: 0.5em ;
  vertical-align: top }

table.docutils th.field-name, table.docinfo th.docinfo-name {
  font-weight: bold ;
  text-align: left ;
  white-space: nowrap ;
  padding-left: 0 }

h1 tt.docutils, h2 tt.docutils, h3 tt.docutils,
h4 tt.docutils, h5 tt.docutils, h6 tt.docutils {
  font-size: 100% }

ul.auto-toc {
  list-style-type: none }

</style>
</head>
<body>
<div class="document" id="graphic-user-interface-faq">
<h1 class="title">Graphic User Interface FAQ</h1>
<table class="docinfo" frame="void" rules="none">
<col class="docinfo-name" />
<col class="docinfo-content" />
<tbody valign="top">
<tr><th class="docinfo-name">Date:</th>
<td>2003-09-04</td></tr>
<tr><th class="docinfo-name">Version:</th>
<td>6607</td></tr>
<tr class="field"><th class="docinfo-name">Web site:</th><td class="field-body"><a class="reference external" href="http://www.python.org/">http://www.python.org/</a></td>
</tr>
</tbody>
</table>
<div class="contents topic" id="contents">
<p class="topic-title first">Contents</p>
<ul class="auto-toc simple">
<li><a class="reference internal" href="#general-gui-questions" id="id1">1&nbsp;&nbsp;&nbsp;General GUI Questions</a><ul class="auto-toc">
<li><a class="reference internal" href="#what-platform-independent-gui-toolkits-exist-for-python" id="id2">1.1&nbsp;&nbsp;&nbsp;What platform-independent GUI toolkits exist for Python?</a><ul class="auto-toc">
<li><a class="reference internal" href="#tkinter" id="id3">1.1.1&nbsp;&nbsp;&nbsp;Tkinter</a></li>
<li><a class="reference internal" href="#wxwindows" id="id4">1.1.2&nbsp;&nbsp;&nbsp;wxWindows</a></li>
<li><a class="reference internal" href="#qt" id="id5">1.1.3&nbsp;&nbsp;&nbsp;Qt</a></li>
<li><a class="reference internal" href="#gtk" id="id6">1.1.4&nbsp;&nbsp;&nbsp;GTk+</a></li>
<li><a class="reference internal" href="#fltk" id="id7">1.1.5&nbsp;&nbsp;&nbsp;FLTK</a></li>
<li><a class="reference internal" href="#fox" id="id8">1.1.6&nbsp;&nbsp;&nbsp;FOX</a></li>
<li><a class="reference internal" href="#opengl" id="id9">1.1.7&nbsp;&nbsp;&nbsp;OpenGL</a></li>
</ul>
</li>
<li><a class="reference internal" href="#what-platform-specific-gui-toolkits-exist-for-python" id="id10">1.2&nbsp;&nbsp;&nbsp;What platform-specific GUI toolkits exist for Python?</a></li>
</ul>
</li>
<li><a class="reference internal" href="#tkinter-questions" id="id11">2&nbsp;&nbsp;&nbsp;Tkinter questions</a><ul class="auto-toc">
<li><a class="reference internal" href="#how-do-i-freeze-tkinter-applications" id="id12">2.1&nbsp;&nbsp;&nbsp;How do I freeze Tkinter applications?</a></li>
<li><a class="reference internal" href="#can-i-have-tk-events-handled-while-waiting-for-i-o" id="id13">2.2&nbsp;&nbsp;&nbsp;Can I have Tk events handled while waiting for I/O?</a></li>
<li><a class="reference internal" href="#i-can-t-get-key-bindings-to-work-in-tkinter-why" id="id14">2.3&nbsp;&nbsp;&nbsp;I can't get key bindings to work in Tkinter: why?</a></li>
</ul>
</li>
</ul>
</div>
<div class="section" id="general-gui-questions">
<h1><a class="toc-backref" href="#id1">1&nbsp;&nbsp;&nbsp;General GUI Questions</a></h1>
<div class="section" id="what-platform-independent-gui-toolkits-exist-for-python">
<h2><a class="toc-backref" href="#id2">1.1&nbsp;&nbsp;&nbsp;What platform-independent GUI toolkits exist for Python?</a></h2>
<p>Depending on what platform(s) you are aiming at, there are several.</p>
<div class="section" id="tkinter">
<h3><a class="toc-backref" href="#id3">1.1.1&nbsp;&nbsp;&nbsp;Tkinter</a></h3>
<p>Standard builds of Python include an object-oriented interface to the
Tcl/Tk widget set, called Tkinter.  This is probably the easiest to
install and use.  For more info about Tk, including pointers to the
source, see the Tcl/Tk home page at <a class="reference external" href="http://www.tcl.tk">http://www.tcl.tk</a>.  Tcl/Tk is
fully portable to the MacOS, Windows, and Unix platforms.</p>
</div>
<div class="section" id="wxwindows">
<h3><a class="toc-backref" href="#id4">1.1.2&nbsp;&nbsp;&nbsp;wxWindows</a></h3>
<p>wxWindows is a portable GUI class library written in C++ that's a
portable interface to various platform-specific libraries; wxPython is
a Python interface to wxWindows.  wxWindows supports Windows and MacOS;
on Unix variants, it supports both GTk+ and Motif toolkits.
wxWindows preserves the look and feel of the underlying graphics
toolkit, and there is quite a rich widget set and collection of GDI
classes.  See <a class="reference external" href="http://www.wxwindows.org">the wxWindows page</a> for more
details.</p>
<p><a class="reference external" href="http://alldunn.com/wxPython">wxPython</a> is an extension module that
wraps many of the wxWindows C++ classes, and is quickly gaining
popularity amongst Python developers.  You can get wxPython as part of
the source or CVS distribution of wxWindows, or directly from its home
page.</p>
</div>
<div class="section" id="qt">
<h3><a class="toc-backref" href="#id5">1.1.3&nbsp;&nbsp;&nbsp;Qt</a></h3>
<p>There are bindings available for the Qt toolkit (<a class="reference external" href="http://www.riverbankcomputing.co.uk/pyqt/">PyQt</a>) and for KDE (PyKDE).
If you're writing open source software, you don't need to pay for
PyQt, but if you want to write proprietary applications, you must buy
a PyQt license from <a class="reference external" href="http://www.riverbankcomputing.co.uk">Riverbank Computing</a> and a Qt license from
<a class="reference external" href="http://www.trolltech.com">Trolltech</a>.</p>
</div>
<div class="section" id="gtk">
<h3><a class="toc-backref" href="#id6">1.1.4&nbsp;&nbsp;&nbsp;GTk+</a></h3>
<p>PyGTk bindings for the <a class="reference external" href="http://www.gtk.org">GTk+ toolkit</a> have been
implemented by by James Henstridge; see
<a class="reference external" href="ftp://ftp.gtk.org/pub/gtk/python/">ftp://ftp.gtk.org/pub/gtk/python/</a>.</p>
</div>
<div class="section" id="fltk">
<h3><a class="toc-backref" href="#id7">1.1.5&nbsp;&nbsp;&nbsp;FLTK</a></h3>
<p>Python bindings for <a class="reference external" href="http://www.fltk.org">the FLTK toolkit</a>, a simple yet powerful
and mature cross-platform windowing system, are available from <a class="reference external" href="http://pyfltk.sourceforge.net">the
PyFLTK project</a>.</p>
</div>
<div class="section" id="fox">
<h3><a class="toc-backref" href="#id8">1.1.6&nbsp;&nbsp;&nbsp;FOX</a></h3>
<p>A wrapper for <a class="reference external" href="http://www.fox-toolkit.org/">the FOX toolkit</a>
called <a class="reference external" href="http://fxpy.sourceforge.net/">FXpy</a> is available.
FOX supports both Unix variants and Windows.</p>
</div>
<div class="section" id="opengl">
<h3><a class="toc-backref" href="#id9">1.1.7&nbsp;&nbsp;&nbsp;OpenGL</a></h3>
<p>For OpenGL bindings, see <a class="reference external" href="http://pyopengl.sourceforge.net">PyOpenGL</a>.</p>
</div>
</div>
<div class="section" id="what-platform-specific-gui-toolkits-exist-for-python">
<h2><a class="toc-backref" href="#id10">1.2&nbsp;&nbsp;&nbsp;What platform-specific GUI toolkits exist for Python?</a></h2>
<p><a class="reference external" href="http://www.python.org/download/download_mac.html">The Mac port</a> by
Jack Jansen has a rich and ever-growing set of modules that support
the native Mac toolbox calls.  The port includes support for MacOS9
and MacOS X's Carbon libraries.  By installing the <a class="reference external" href="http://pyobjc.sourceforge.net">PyObjc Objective-C
bridge</a>, Python programs can use
MacOS X's Cocoa libraries. See the documentation that comes with the
Mac port.</p>
<p><a class="reference external" href="http://www.python.org/windows">Pythonwin</a> by Mark Hammond
includes an interface to the Microsoft Foundation
Classes and a Python programming environment using it that's written
mostly in Python.</p>
</div>
</div>
<div class="section" id="tkinter-questions">
<h1><a class="toc-backref" href="#id11">2&nbsp;&nbsp;&nbsp;Tkinter questions</a></h1>
<div class="section" id="how-do-i-freeze-tkinter-applications">
<h2><a class="toc-backref" href="#id12">2.1&nbsp;&nbsp;&nbsp;How do I freeze Tkinter applications?</a></h2>
<p>Freeze is a tool to create stand-alone applications.  When freezing
Tkinter applications, the applications will not be truly stand-alone,
as the application will still need the Tcl and Tk libraries.</p>
<p>One solution is to ship the application with the tcl and tk libraries,
and point to them at run-time using the TCL_LIBRARY and TK_LIBRARY
environment variables.</p>
<p>To get truly stand-alone applications, the Tcl scripts that form
the library have to be integrated into the application as well. One
tool supporting that is SAM (stand-alone modules), which is part
of the Tix distribution (<a class="reference external" href="http://tix.mne.com">http://tix.mne.com</a>). Build Tix with SAM
enabled, perform the appropriate call to Tclsam_init etc inside
Python's Modules/tkappinit.c, and link with libtclsam
and libtksam (you might include the Tix libraries as well).</p>
</div>
<div class="section" id="can-i-have-tk-events-handled-while-waiting-for-i-o">
<h2><a class="toc-backref" href="#id13">2.2&nbsp;&nbsp;&nbsp;Can I have Tk events handled while waiting for I/O?</a></h2>
<p>Yes, and you don't even need threads!  But you'll have to
restructure your I/O code a bit.  Tk has the equivalent of Xt's
XtAddInput() call, which allows you to register a callback function
which will be called from the Tk mainloop when I/O is possible on a
file descriptor.  Here's what you need:</p>
<pre class="literal-block">
from Tkinter import tkinter
tkinter.createfilehandler(file, mask, callback)
</pre>
<p>The file may be a Python file or socket object (actually, anything
with a fileno() method), or an integer file descriptor.  The mask is
one of the constants tkinter.READABLE or tkinter.WRITABLE.  The
callback is called as follows:</p>
<pre class="literal-block">
callback(file, mask)
</pre>
<p>You must unregister the callback when you're done, using</p>
<pre class="literal-block">
tkinter.deletefilehandler(file)
</pre>
<p>Note: since you don't know <em>how many bytes</em> are available for reading,
you can't use the Python file object's read or readline methods, since
these will insist on reading a predefined number of bytes.  For
sockets, the recv() or recvfrom() methods will work fine; for other
files, use os.read(file.fileno(), maxbytecount).</p>
</div>
<div class="section" id="i-can-t-get-key-bindings-to-work-in-tkinter-why">
<h2><a class="toc-backref" href="#id14">2.3&nbsp;&nbsp;&nbsp;I can't get key bindings to work in Tkinter: why?</a></h2>
<p>An often-heard complaint is that event handlers bound to events
with the bind() method don't get handled even when the appropriate
key is pressed.</p>
<p>The most common cause is that the widget to which the binding applies
doesn't have &quot;keyboard focus&quot;.  Check out the Tk documentation
for the focus command.  Usually a widget is given the keyboard
focus by clicking in it (but not for labels; see the takefocus
option).</p>
</div>
</div>
</div>
</body>
</html>
